A shoe is generally formed of an upper, a lower attached to the upper, and an outsole attached to the lower. The outsole of the shoe is the exposed portion of the sole that contacts the ground or other supporting surface. The outsole provides many characteristics of the shoe such as the shoe's traction and stability with respect to the intended supporting surface. For example, the outsole of the shoe may be provided with some type of traction elements arranged in a pattern to provide a gripping action between the outsole and the ground or supporting surface. The outsole should also be manufactured so that it offers extended wear to permit the shoe to be worn for a lengthy period of time.
Often, the outsole of the shoe is formed of a rubber material or leather in designer shoes and the like. In men's and women's shoes, the outsole is very often substantially smooth and this can cause traction problems. For example, such outsoles are often very slippery because of their smooth texture and this increases the chances that the user may accidently slip or slide during normal use. The risk of slipping and sliding is increased significantly when the surface or supporting surface is wet or otherwise in a slippery state.
The outsole is an important component of the shoe for an additionally entirely unrelated reason which has gone unrecognized in the art of shoe sole construction. As the economies of most countries become more and more internationalized, international commercial transactions invoke national customs tariffs that generally must be paid when goods are shipped. Under the Harmonized Tariff Schedules of each country, goods are classified under various categories. For example, most footwear is classified under Chapter 64 of the United States Harmonized Tariff Schedules which covers the importation of goods into the United States. Within this chapter, the following major headings are recited for footwear:
 6401 Waterproof Rubber or Plastic Footwear;6402Other Footwear with Uppers and Outersoles ofRubber or Plastic;6403Footwear with Uppers of Leather and OutersolesOf Rubber, Plastic, Leather, or Composition Leather;6404Footwear with Uppers of Textiles and Outersoles ofRubber, Plastic, Leather, or Composition Leather; and6405Other Footwear.Accordingly, footwear is generally classified in a given heading based upon the material of the upper and the material of the outersole. Consequently, the outsole plays an important role in determining the rate of duty which is to be applied to the specific footwear article. Depending upon the material which is used to manufacture the upper and the sole, the rate of the duty may vary significantly. For example, the rate of duty may range from 37.5% ad valorem for many common types of footwear to 3% ad valorem for certain types of sandals and similar footwear. In determining the applicability of a particular section of one chapter of the United States Harmonized Tariff Schedules, knowledge of specific details of the material is necessary. For example, a classification may be based on the type of material that is present on 50% or more of the bottom surface of the shoe (outersole) that contacts the ground.
Over many years, manufacturers have focused their attention on improving the traction properties of shoe outsole construction, but have not recognized that a price advantage can be had by combining materials in the outer shoe sole construction.
What is needed in the art and has heretofore not been available is an outsole and method of manufacture thereof which offers slip resistance and other desirable properties in addition to providing a competitive advantage to the manufacturer based on its construction.